Formaldehyde, which is found in both cigarette smoke and automobile tailpipe emissions, has been classified as a probable human carcinogen by the Environmental Protection Agency (EPA), and it is a known human carcinogen by the Department of Health and Human Services, according to The National Cancer Institute.

The recent findings by France's National Consumer Institute reinforced concerns expressed by the U.S. Food and Drug Administration in 2009, when the agency issued a warning that ingredients in anti-freeze were found in some e-cigarette samples.

"This is not a reason to ban them, but to place them under better control," National Consumer Institute Editor Thomas Laurenceau said.

In light of its findings, the FDA is considering new potential regulations for the e-cigarettes, which are currently sold online and lack many of the restrictions cigarette companies have, due to the fact that the product does not include tobacco.

On a local level, several municipalities have already enacted or considered restrictions on the sales of e-cigarettes due to the FDA's warnings.

The proposed bills would increase the minimum age to purchase e-cigarettes from 18 to 21, prohibit stores from displaying e-cigarette ads, and raise the cost of a pack of e-cigarettes to a base price of $10.50 in NYC.

Additionally, the Seal Beach, CA city council on Tuesday announced a 45-day ban on the sale of e-cigarettes to allow for them to examine the potential health risks of the devices, KTLA reported.

Despite the concerns, the sales of e-cigarettes have boomed in recent years, with the industry recording more than $1 billion in sales in 2012, Yahoo News reported.

As the demand for alternatives to cigarettes grows, profits are expected to increase exponentially. Some predict $10 billion in revenue for the e-cigarette industry in the next five years.